The present invention relates to cabin ventilation air outlets and more particularly to passenger cabin air outlets located in the cabin ceiling which blow air downward toward the passengers without causing drafts perceivable by passengers.
Problem Solved by the Invention
Prior main deck air distribution outlets were incorporated into the outboard and inboard stowage bins respectively. These locations represented the best placement for the outlets as it enabled the outlet to produce air jets with the maximum possible throw before reaching the seated passenger areas. The air jets are also projected in a horizontal direction and the airflow is initially attached to the stowage bins. This reduces the tendency of the jets to be affected by buoyancy forces.
In an effort to design flexible cabin interiors, the air distribution outlets have been relocated to the ceiling area. This was done to make the air distribution system independent of the stowbin configurations so that the lavatories and galleys could be reconfigured without changing the air distribution system.
This change brought the air outlets closer to the passenger seated area and reduces the required throw of the jet. A broad slow moving jet is required for this application to provide acceptable velocities in the seated areas. However, as the jet is now projected vertically and as the low velocity jet will entrain less cabin air, the jet velocities will be greatly affected by temperature differences between the supply air and cabin. During a heating mode, the jet velocity will be insufficient to overcome buoyancy effects and it will be unable to thoroughly penetrate the cooler cabin. This will result in adverse temperature gradients within the cabin. During a cooling mode, the velocities will be sufficient to project to the cabin wall and may cause a draft in the passenger seated areas.
Additionally, large dimensions required to produce a broad low velocity jet will result in a nozzle that is not aesthetically pleasing and too heavy.
Previous Attempts to Solve the Problem
Prior attempts to solve the problem resulted in nozzle designs as described above. The nozzle designs to some degree have had the problems similar to those described above.
Passenger cabin ventilation air outlets located in the cabin ceiling for blowing air downward toward the passengers. The cabin ventilation air outlets entrain surrounding cabin air without causing drafts perceivable by passengers. A series of high velocity jets exiting from a narrow ceiling nozzle entrain cabin air to form a slow moving single jet, the slow moving jet providing draft mitigation.
Preferred Embodiment of the Invention
Three rows of slots are disposed within an inverted extruded chamber feeding the outlet nozzle. The outer rows of slots producing a wide air jet, the center row utilized to draw the outer jets back together outside the nozzle.